Table 3.

Association of abnormal maternal serum analytes in relation to placental abruption with and without co-occurring ischemic placental disease

	No IPD	Placental abruption only			Abruption with preeclampsia or FGR
	No. (%)	No. (%)	Risk ratio (95% CI)		No. (%)	Risk ratio (95% CI)
			Unadjusted	Adjusted		Unadjusted	Adjusted
PAPP-A ≤5 percentile	1,745 (6.1)	20 (10.6)	1.8 (1.2–2.9)	1.8 (1.2–2.9)	4 (16.7)	3.1 (1.1–9.0)	2.8 (1.0–8.3)
Maternal serum AFP ≥95 percentile	1,556 (5.8)	20 (10.4)	1.9 (1.2–3.0)	1.8 (1.1–3.1)	3 (15.0)	2.9 (0.8–9.8)	2.7 (0.8–9.2)
Inhibin-A ≤5 percentile	1,630 (6.0)	18 (10.2)	1.8 (1.1–2.9)	1.8 (1.1–2.9)	1 (7.1)	0.5 (0.2–9.2)	1.3 (0.2–9.8)
Inhibin-A ≥95percentile	1,484 (5.5)	15 (8.7)	1.6 (1.0–2.8)	1.6 (0.9–2.7)	8 (38.1)	10.5 (4.4–25.3)	8.3 (3.4–21.1)

IPD, ischemic placental disease; FGR, fetal growth restriction; PAPP-A, pregnancy-associated plasma protein A; AFP, alpha fetoprotein; CI, confidence interval

Risk ratios are adjusted for maternal age, age-squared, primiparity, maternal education, single marital status, race-ethnicity, and smoking, with “no ischemic placental disease” as the reference group